Turbofan and air conditioner having the same

ABSTRACT

A turbofan to reduce a blowing noise, and an air conditioner having the same. The turbofan includes a rotating plate coupled to a shaft of a driving motor, a plurality of blades coupled to an outer circumference of the rotating plate, and an annular shroud coupled to an end of each blade. The end of each blade includes an inner end that is coupled to the rotating plate, and an outer end that is not coupled to the rotating plate. The outer end of each blade is tilted toward the rotating plate such that a distance between the outer end of each blade and an inner surface of an apparatus employing the turbofan is increased as the outer end of each blade moves away from a rotational center of the rotating plate in a radial outward direction.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority under 35 U.S.C. § 119(a) from Korean Patent Application No. 2006-114806, filed on Nov. 20, 2006, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein in its entirety by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present general inventive concept relates to a conventional turbofan and an air conditioner having the same, and more particularly to a turbofan and an air conditioner having the same, capable of reducing blowing noises.

2. Description of the Related Art

A conventional turbofan is a type of centrifugal fan, which is adapted to radially blow air in an axial direction, and is used to blow air in a refrigerator, an air conditioner, a vacuum cleaner, etc.

A turbofan applied to an air conditioner is disclosed in Korean Patent Application Publication No. 2002-19160. This turbofan includes a rotating plate having a hub in the middle thereof, a plurality of blades coupled to the rotating plate, and a circular shroud connecting the blades. Further, the turbofan is formed such that an outer diameter of the rotating plate is smaller than an inner diameter of the shroud. This makes it possible to integrally form the rotating plate, the blades, and the shroud by means of ordinary injection molding, and to easily separate the turbofan from a mold after the molding.

However, as illustrated in FIG. 1, because a turbofan is formed such that the outer diameter of a rotating plate 1 is smaller than an inner diameter of a shroud 2, noise is caused by a vortex generated from a lower outer end 3 a of each of a plurality of blades 3 during operation of the turbofan. When the turbofan is installed in, for instance, an air conditioner, the lower outer end 3 a of each of the plurality of blades 3 becomes adjacent to an inner surface of a case 4 of the air conditioner. Accordingly, because the vortex generated from the lower end 3 a of each of the plurality of blades 3 hits the inner surface of the case 4, the vortex can cause a blowing noise. In particular, as illustrated in FIG. 1, when the lower end 3 a of each blade 3 is parallel to the inner surface of the case 4, the blowing noise caused by the vortex can be increased.

SUMMARY OF THE INVENTION

The present general inventive concept provides a turbofan and an air conditioner having the same, capable of reducing blowing noises.

Additional aspects and utilities of the present general inventive concept will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the general inventive concept.

The foregoing and/or other aspects and utilities of the present general inventive concept are achieved by providing a turbofan, which includes a rotating plate coupled to a shaft of a driving motor, a plurality of blades coupled to an outer circumference of the rotating plate, and an annular shroud coupled to an end of each blade. The end of each blade may include an inner end that is coupled to the rotating plate, and an outer end that is not coupled to the rotating plate. The outer end of each blade may be tilted toward the rotating plate such that a distance between the outer end of each blade and an inner surface of an apparatus employing the turbofan is increased as the outer end of each blade moves away from a rotational center of the rotating plate in a radial outward direction.

The outer end of each blade may have a tilt angle of about 5 degrees to about 15 degrees with respect to the rotating plate.

The rotating plate, the blades, and the shroud may be integrally formed.

The foregoing and/or other aspects and utilities of the present general inventive concept may also be achieved by providing an air conditioner, which includes a main body case, a driving motor fixed to an inner surface of the main body case, a turbofan coupled to a shaft of the driving motor, and a heat exchanger installed around the turbofan in the main body case. The turbofan may include a rotating plate coupled to the shaft of the driving motor, a plurality of blades coupled to an outer circumference of the rotating plate, and an annular shroud coupled to an end of each blade. The end of each blade may include an inner end that is coupled to the rotating plate, and an outer end that is not coupled to the rotating plate. The outer end of each blade may be tilted toward the rotating plate such that a distance between the outer end of each blade and an inner surface of the main body case is increased as the outer end of each blade moves away from a rotational center of the rotating plate in a radial outward direction.

The foregoing and/or other aspects and utilities of the present general inventive concept may also be achieved by providing a turbofan assembly, including a main body, a rotating plate coupled to an inner surface of the main body to rotate on an axis perpendicular to the inner surface, and a plurality of blades coupled to an outer circumference of the rotating plate, each of the plurality of blades including a side closest to the inner surface of the main body which gradually slopes away from the inner surface of the main body as the side extends away from the rotating plate.

The foregoing and/or other aspects and utilities of the present general inventive concept may also be achieved by providing a turbofan assembly, including a main body, a rotating plate coupled to an inner surface of the main body to rotate on an axis perpendicular to the inner surface, and a plurality of blades each having an inner side with respect to the main body that includes a first end coupled to an outer circumference of the rotating plate and a second end which is at a distance further from the inner surface of the main body than the first end.

The foregoing and/or other aspects and utilities of the present general inventive concept may also be achieved by providing an air conditioner, including a main body case, a driving motor fixed to an inner surface of the main body case, a rotating plate coupled to the driving motor to rotate on an axis perpendicular to the inner surface of the main body case, and a plurality of blades coupled to an outer circumference of the rotating plate, each of the plurality of blades including a side closest to the inner surface of the main body case which gradually slopes away from the inner surface of the main body case as the side extends away from the rotating plate.

BRIEF DESCRIPTION OF THE DRAWINGS

These and/or other aspects and utilities of the present general inventive concept will become apparent and more readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which:

FIG. 1 is a sectional view illustrating a blade structure of a conventional turbofan;

FIG. 2 is a sectional view illustrating a ceiling type air conditioner to which a turbofan according to an embodiment of the present general inventive concept is employed;

FIG. 3 is a perspective view illustrating a turbofan according to an embodiment of the present general inventive concept;

FIG. 4 is a sectional view illustrating a turbofan according to an embodiment of the present general inventive concept; and

FIG. 5 is a detailed sectional view illustrating a blade structure of a turbofan according to an embodiment the present general inventive concept.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Reference will now be made in detail to the embodiments of the present general inventive concept, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the like elements throughout. The embodiments are described below in order to explain the present general inventive concept by referring to the figures.

FIG. 2 is a sectional view illustrating a ceiling type air conditioner to which a turbofan according to the present general inventive concept is employed. As illustrated in FIG. 2, the air conditioner includes a box-like main body case 10 fitted in a ceiling 100, and a ceiling panel 20 that is coupled to an open lower surface of the main body case 10 and covers an opening of the ceiling on the circumference thereof.

The main body case 10 is provided therein with a turbofan 40 to draw air from below the air conditioner in an upward direction through a center portion thereof and discharge the air in a radial direction, and a driving motor 11 to drive the turbofan 40. The driving motor 11 is fixed to an inner upper surface of the main body case 10. Further, a heat exchanger 12 is installed around the turbofan 40 to exchange heat with the air discharged from the turbofan 40. A condensed water drain 13, which may collect and drain condensed water that is generated during exchanging heat, is installed under the heat exchanger 12. The condensed water drain 13 is supported by the ceiling panel 20.

The ceiling panel 20 may include an inlet 21 to draw indoor air upward at the center of the air conditioner, and a plurality of narrow long outlets 22 around the inlet 21. Further, a filter 23 to clean the air may be installed in the inlet 21 of the ceiling panel 20. An air guide plate 24, which includes an opening 24 a at a center portion thereof, is installed inside the filter 23 to guide the drawn air toward the center of the turbofan 40.

As illustrated in FIGS. 2 through 4, the turbofan 40 includes a circular rotating plate 41 including a hub 41 a with a center portion thereof coupled to a shaft 11 a of the driving motor 11, a plurality of blades 42 that are coupled to a front outer circumference of the rotating plate 41 and are disposed in a radial direction, and an annular shroud 43 (see FIG. 4) that is coupled to an end of each blade 42 which is opposite to the rotating plate 41.

As illustrated in FIGS. 4 and 5, the turbofan 40 may be formed such that an outer diameter D1 of the rotating plate 41 is equal to or less than an inner diameter D2 of the shroud 43.

Constructing the turbofan 40 according to embodiments of the present general inventive concept is provided so that the diameter D1 of the rotating plate 41 is equal to or less than an inner diameter D2 of the shroud 43 prevents an undercut (e.g., a portion where a molded product can not be ejected by means of parallel movement of a mold) from being generated from the mold when the turbofan 40 is molded by injection molding, so that the rotating plate 41, the blades 42, and the shroud 43 can be integrally formed.

As illustrated in FIG. 5, because the turbofan 40 is formed such that the outer diameter D1 of the rotating plate 41 is less than the inner diameter D2 of the shroud 43, an end of each blade 42 which is located on the side of the rotating plate 41 may include an inner end 45 that is coupled to the rotating plate 41, and an outer end 46 that is not coupled to the rotating plate 41. The outer end 46 of each blade 42, which is located on the side of the rotating plate 41, may be formed to have a predetermined tilt angle θ with respect to the rotating plate 41. The tilt angle θ may range from approximately 5 degrees to approximately 15 degrees. This makes it possible to minimize a blowing noise caused by a vortex generated around the outer end 46 of each blade 42 by gradually increasing a distance between the outer end 46 of each blade 42 and the inner surface of the main body case 10 as the outer end 46 of each blade 42 moves away from the rotational center of the rotating plate 41 in a radial outward direction.

When the turbofan 40 is driven, the vortex is generated around the outer end 46 of each blade 42, and grows stronger and stronger as it moves in a radial outward direction. The present general inventive concept is adapted to make the outer end 46 of each blade 42 tilt in proportion to a growth of the vortex, so that the vortex generated around the outer end 46 of each blade 42 can strike the inner surface of the main body case 10 to a minimum extent, thereby reducing the blowing noise.

Now, reference will be made to an operation of the ceiling type air conditioner to which the turbofan is employed.

As illustrated in FIG. 2, when the driving motor 11 is driven to rotate the turbofan 40, indoor air is drawn through the central inlet 21 of the ceiling panel 20. The drawn indoor air is cleaned while passing through the filter 23, and then flows to the turbofan 40 through the opening 24 a of the air guide plate 24. The air is rotated and discharged toward the circumference of the turbofan 40 (i.e. toward the heat exchanger) by means of the rotational force of the turbofan 40. The air discharged from the turbofan 40 is cooled while passing through the heat exchanger 12, and then is supplied into the indoor space through the outlets 22 again.

As illustrated in FIG. 5, the air blown by the turbofan 40 during the operation as described above with reference to FIG. 2, is discharged in a radial direction of the turbofan 40, and simultaneously toward the outer end 46 of each blade 42 which is located at a side of the rotating plate 41. At this time, the vortex generated around the outer end 46 of each blade 42 grows stronger and stronger due to the centrifugal force as it moves in a radial outward direction. Because the outer end 46 of each blade 42 is tilted in proportion to the growth of the vortex, the present general inventive concept can minimize a collision of the vortex and the inner surface of the main body case 10, thereby reducing blowing noises.

As described in detail above, because an outer end of each of a plurality of blades is tilted in proportion to the growth of a vortex, a turbofan according to the present general inventive concept can minimize collision of the vortex generated around the outer end of each of the plurality of blades and a main body case, and thereby can reduce a blowing noise.

Although a few embodiments of the present general inventive concept have been shown and described, it will be appreciated by those skilled in the art that changes may be made in these embodiments without departing from the principles and spirit of the general inventive concept, the scope of which is defined in the appended claims and their equivalents. 

1. A turbofan, comprising; a rotating plate coupled to a shaft of a driving motor; a plurality of blades coupled to an outer circumference of the rotating plate; and an annular shroud coupled to an end of each blade, the end of each blade including an inner end that is coupled to the rotating plate, and an outer end that is not coupled to the rotating plate, wherein the outer end of each blade is tilted toward the rotating plate such that a distance between the outer end of each blade and an inner surface of an apparatus employing the turbofan increases as the outer end of each blade moves away from a rotational center of the rotating plate in a radial outward direction.
 2. The turbofan of claim 1, wherein the outer end of each blade has a tilt angle of about 5 degrees to about 15 degrees with respect to the rotating plate.
 3. The turbofan of claim 2, wherein the rotating plate, the blades, and the shroud are integrally formed.
 4. An air conditioner, comprising: a main body case; a driving motor fixed to an inner surface of the main body case; a turbofan coupled to a shaft of the driving motor; and a heat exchanger installed around the turbofan in the main body case, wherein the turbofan includes a rotating plate coupled to the shaft of the driving motor, a plurality of blades coupled to an outer circumference of the rotating plate, and an annular shroud coupled to an end of each blade wherein the end of each blade includes an inner end that is coupled to the rotating plate, and an outer end that is not coupled to the rotating plate, and wherein the outer end of each blade is tilted toward the rotating plate such that a distance between the outer end of each blade and an inner surface of the main body case is increased as the outer end of each blade moves away from a rotational center of the rotating plate in a radial outward direction.
 5. The air conditioner of claim 4, wherein the outer end of each blade has a tilt angle of about 5 degrees to about 15 degrees with respect to the rotating plate.
 6. The air conditioner of claim 5, wherein the rotating plate, the blades, and the shroud are integrally formed.
 7. A turbofan assembly, comprising: a main body; a rotating plate coupled to an inner surface of the main body to rotate on an axis perpendicular to the inner surface; and a plurality of blades coupled to an outer circumference of the rotating plate, each of the plurality of blades including a side closest to the inner surface of the main body which gradually slopes away from the inner surface of the main body as the side extends away from the rotating plate.
 8. A turbofan assembly, comprising: a main body; a rotating plate coupled to an inner surface of the main body to rotate on an axis perpendicular to the inner surface; and a plurality of blades each having an inner side with respect to the main body that includes a first end coupled to an outer circumference of the rotating plate and a second end which is at a distance further from the inner surface of the main body than the first end.
 9. An air conditioner, comprising: a main body case; a driving motor fixed to an inner surface of the main body case; a rotating plate coupled to the driving motor to rotate on an axis perpendicular to the inner surface of the main body case; and a plurality of blades coupled to an outer circumference of the rotating plate, each of the plurality of blades including a side closest to the inner surface of the main body case which gradually slopes away from the inner surface of the main body case as the side extends away from the rotating plate. 